Lactulose and mannitol intestinal permeability detected by capillary electrophoresis

Aim of this study was to set up a method by capillary electrophoresis to detect lactulose and mannitol in urine after an oral load, and to estimate the intestinal permeability in controls and in type I diabetes patients. The underivatized carbohydrates were monitored by indirect UV detection using sorbate, cetyltrimethylammonium bromide and LiOH as background electrolyte. Urines were purified by solid phase extraction, shaken with cation exchange resin, filtered and analysed. Carbohydrates migrated in <10 min in relation to their pKa and Mr. Controls (n = 33) and patients (n = 23) had an excretion ratio lactulose/mannitol 0.025 (0.018–0.051) and 0.067 (0.050–0.127), respectively (p < 0.01, median, interquartile range).